As March progresses and the weather starts warming, overnight frost poses a significant risk to area trees, especially fruit trees.

By MARK SPENCLEYmark@cheboygantribune.com

As March progresses and the weather starts warming, overnight frost poses a significant risk to area trees, especially fruit trees.In 2012, several weeks of warm, summer-like weather coaxed area trees into budding their leaves, but a couple of hard frosts damaged many buds and blossoms. “If you’re at a point when most trees are ready to break bud, a hard frost can have an impact,” said Roger Mech, forest health specialist with the Department of Natural Resources. “It really varies depending on the conditions in a specific area.”The severity of the frost goes a long way in determining if there will be any damage to the summer health of trees. As one would expect, sustained sub-freezing temperatures can cause havoc. If temperatures only dip below freezing for a few hours, the impact will be much less noticeable. “What you could see is leaves looking a little tattered of misshapen when they emerge, but that doesn’t have a real impact of the tree,” Mech added. “There would be a little less leaf area for creating photosynthesis, but the leaves will grow out as the season goes on.”If temperatures were to dip lower than expected, say into the teens over a few consecutive nights, the impact on the tree would be much greater. Two decades ago, a cold snap hit northern Michigan in late May, according to Mech. The result was widespread defoliation and stunted tree growth. The same events occurred last spring.“It was in the early 90s and we had a few nights in a row where temperatures dropped into the low teens, really cold,” he explained. “A lot of trees lost their leaves and had to re-flush. That’s really stressful on a tree. They have to pull sugar stores from their roots that would normally be used to grow wood. It’s a hard process on a tree.”Fruit tree blossoms and trees in low-lying areas are the most susceptible to damage during a spring frost.If northern Michigan gets the rapid warm up most residents are hoping for, it could prompt leaves into budding a little early. Weather isn’t the only factor though. The amount of daylight is a key player in the commencement of natural processes.“Photoperiod is important and it kind of keeps things in check from year to year,” Mech explained. “Weather can vary greatly, as we’ve seen, but daylight is pretty much the same from year to year.”If a late frost strikes again this spring, it could leave the local fruit industry in a difficult situation. Last year, much of the apple and cherry crop was eliminated in March. Hopefully that’s not the case again this year.